Chimney caps are widely used on the tops of chimney flues to prevent, or at least restrict, entry of rain, snow, hail, leaves, small animals and other undesirable substances and objects into the chimney flue. Chimney caps also prevent birds and squirrels from nesting in an infrequently used chimney. Conventional chimney caps are usually made from sheet metal and include a mounting base portion that is configured to enable the chimney cap to be fitted over and attached to the upper edge of the chimney flue, a perforated cage portion that extends upwardly from the mounting base portion and allows smoke to pass from the flue to the ambient atmosphere but keeps out birds, squirrels, leaves and the like, and a roof that covers the outlet of the flue and restricts the entry of precipitation into the flue. A common way of manufacturing the mounting base and cage portions is by bending a single sheet or blank of metal into the four sides in succession and joining the opposite ends of the bent blank. The roof of the cap is typically welded to the upper ends of the four sides of the cage portion to form a single finished unit. In some chimney caps, the mounting base portion includes inwardly extending flanges that are formed integrally or formed separately and welded to the bottom edge of each side of the cage portion to form a shelf, which is received on top of the chimney flue and supports the cap. The cap is secured by screws on each side of the mounting base portion to hold the cap in place on the flue.
Most chimney caps are preassembled by the manufacturer to create large single units. The manufactured caps when assembled are very bulky for purposes of both storage and shipment. Boxed, assembled caps will take up a large amount of costly space in storage warehouses and retail stores and cargo space in trucks when transported. The individual boxing of fully assembled chimney caps also involves high costs for boxes and the labor costs of individual boxing.
It is also previously known to produce and sell chimney caps in disassembled or kit form, which are assembled at the point of sale or installation. One such chimney cap kit is described and shown in U.S. Pat. No. 5,876,276. A kit form of chimney cap is usually shipped in multiple pieces, typically including four individual side pieces and a hood, along with screws for securing the cap to the chimney flue and nuts and bolts for attaching the hood to the four side walls. The hood is typically connected to each of the side walls by placing the bolt through the sidewall and the hood and installing a nut on the bolt. Welding operations are, of course, not practical for assembling a chimney cap kit at the point of sale or installation.
Chimney caps sold in disassembled or kit form save significant storage and shipping space, which in turn reduces the costs associated with the distribution of the caps. However, because the separate cap side walls are assembled using screws, they generally lack the structural integrity of a welded cap and require additional costs for assembly, whether at the point of purchase or the place of installation.
There is a need for a chimney cap that has the strength and durability of a factory-assembled cap, preferably of a welded construction, that does not require time-consuming assembly operations at the point of sale or installation, and that can be warehoused, shipped and stocked with a considerable reduction in the amount of space.